1. Field of the Invention
This invention relates to alarm and security systems which communicate with a base station and more particularly to such systems which communicate with a base station over a radio frequency and receive information from existing panels which transmit over telephone lines.
2. Previous Art
Alarm and security systems have existed for many years. In fact, there are many such systems which protect commercial and residential buildings today. Most of these systems include a communications panel which is connected to a series of sensors or detectors for gathering information about one or more desired conditions in one or more geographical areas. The panel communicates the gathered information in the form of a digital message to a base station by telephone line.
Typically, the telephone line is the weak link in the security and alarm system. The telephone line is vulnerable to tampering. An intruder can cut the telephone line, place a voltage thereon and trick the panel as to the intruder's presence. Other disadvantages of the telephone line based alarm and security system include the inherent necessity of having a telephone system in place. In many foreign countries and even in remote areas of the U.S. and other developed countries, there are no such telephone systems. Thus, the typical telephone based alarm and security system is useless under those conditions.
Additionally, telephone line based alarm and security systems are quite costly because they required telephone hook-up and considerable hard wiring. And such telephone line based alarm and security systems typically fail during local emergencies such as a power failures (blackouts) and earthquakes.
Additionally, radio reception transmission of condition and control information was not well known in alarm and security systems many years ago. Technology has advanced considerably, virtually obsoleting systems which are incapable of using radio frequency transmissions. This leaves the many thousands of users with such systems of facing the unhappy prospect of purchasing entirely new alarm and security systems.
Examples of existing alarm systems using cellular technology include Millsap et al, U.S. Pat. No. 4,577,182 and Lebowitz, U.S. Pat. No. 4,825,457. Millsap et al discloses an alarm system which uses cellular transmitters to send condition information to a base station. Additionally, Lebowitz discloses the use of cellular network to transmit and receive information. Neither of the above disclosures reveal the use of an existing system in conjunction with their systems.
What is needed is an alarm and security system which can stand on its own and function as a secure system. Such a system should include a panel with the ability to communicate with the base station via either telephone or radio transmission. Additionally what is needed is an alarm and security system which can be used in conjunction with existing panels such that the existing panels can be used compatibly with modern technology.